Trim the top layer of fat from the short ribs. Place several pieces of this fat in a Dutch oven, and cook over medium heat until bottom is lightly coated with fat, and remove the pot from the heat. Sprinkle the short ribs with salt, brown them on all sides, and then removing them when they are done. Add the onion and slightly saute until lightly browned. Return the short ribs to the pot and add the ketchup, water, lemon juice, sugar, mustard, salt, and Worcestershire sauce. Cover the pot and cook over low heat for 2 hours, or until tender, stirring occasionally.